A conventional sealing assembly for an inlet valve of a power nailer is shown in FIG. 1, wherein the inlet valve generally includes a fixed frame 200 which fixedly attached to the end opposite to the nail ejecting end of the barrel, and a movable member 300 which is movably engaged with the fixed frame 200 and biased by a spring 330. The fixed frame 200 is a ring-shaped member and has a first annular flange 210 extending from the outside thereof and a second annular flange 220 extending from one of two sides of the fixed frame 200. The movable member 300 has a shape similar to that of the fixed frame 200 and includes a third annular 320 flange extending from the outside thereof so as to movably engage with the inside of the first annular flange 210, and a fourth annular flange 310 which is inserted through the central hole of the ring-shaped fixed frame 200. The spring 330 is biased between the end cap 400 and one of two sides of the movable member 300. A first seal 600 is received between the second annular flange 220 and the fourth annular flange 310, and a second seal 500 is engaged with the distal edge of the first annular flange 210 and the other side of the movable member 300. The first seal 600 has two contact points 610, 630 movably contact the fourth annular flange 310 of the movable member 300, and the other two contact points 620, 640 contact the second annular flange 220 of the fixed frame 200. The second seal 500 has a deformable portion 530 which allows the second seal 500 to be deformed without disengaging from the fixed frame 200 or the movable member 300 while the movable member 300 is moved reciprocatingly.
A piston 700 with a driving shaft 710 is movably received in the cylinder 720. The cylinder 720 has one end thereof that the nails (not shown) are ejected by the driving shaft 710, and the other end thereof which is connected to the movable member 300. When the trigger (not shown) is pulled, the high pressure air enters into the space between the movable member 300 and the piston 700 so as to push the piston 700 to eject the nail and, in the same time, the movable member 300 is moved to compress the spring 330. When the trigger is released, the movable member 300 is biased by the spring 330 to be moved toward the cylinder 720.
When the high pressure air enters into the barrel, the first seal 600 is expanded and the inner periphery including the two contact points 610, 630 is attached to the fourth annular flange 310 so that the frictional force between the first seal 600 and the fourth annular flange 310 of the movable member 300 is large.
Furthermore, when the movable member 300 is moving, the second seal 500 is stretched between the distal edge of the first annular flange 210 and the movable member 300. The second seal 500 could be broken after being used for a period of time.
The present invention intends to provide a seal assembly which includes two seals respectively connected between the movable member and the fixed frame, and provides less frictional force between the movable member and the fixed frame.
The present invention has arisen to mitigate and/or obviate the disadvantages of the conventional sealing assembly of a power nailer.